When you say "foveated compression" do you mean
>Apple will liberally use an already-known VR technique that involves using eye-tracking to render objects in the user's periphery at a lower fidelity than what the user is focusing on.
?
Due to latency, you can't render the fovea area only; you need to cover quite a bit more in case the eye moves between submitting the command buffer and the final image being ready.
Compression can happen much later in the process, where the latency is much more predictable or even fixed. This is useful because massive bandwidth is easiest along traces, harder along wires and hardest wirelessly.